1. Field of the Invention
The present invention relates to a stainless steel container having a rubber protector, which is used for storing beverage such as beer, etc.
2. Description of the Prior Art
As a container in which various kinds of beverages including beer are filled and which is intended to be used for storing in stationary place or transportation, a stainless steel container has been generally used. The upper and lower outer peripheral edges of a container body are fitted with ring shaped protectors, respectively. The protectors cover the periphery of an upper end wall and that of a lower end wall of the container body to protect end wall faces of the upper end wall and the lower end wall. In use, a lower protector provided at the lower end wall serves for a stand for stationarily placing the container and an upper protector provided at the upper end wall serves for a supporting base for a container to be piled above.
The protector has been conventionally manufactured by mainly using a stainless steel material which is the same one as the container body. The stainless steel protectors have been usually welded to an upper peripheral edge and a lower peripheral edge of the stainless steel container body which has been worked under deep-drawing. Another example the protector is that an upper end wall and a lower end wall are welded to a lower inner peripheral face and an upper inner peripheral face of a stainless steel cylinder so that the upper end wall overhangs upwardly and the lower end wall overhangs downwardly to form protector portions.
In either cases of the above, when a protector is made from a stainless steel, it is stout and good-looking. However, when, for example, draft beer is filled in a container, the weight of the container becomes considerably heavy. Thus, when a container is erroneously dropped at the time of loading-in or loading-out of containers to be transported or the container is striken hard against a floor, not only a noise is given forth, but also the container is deformed or damaged. Especially, when the container is dropped in an inclined state, the protector is locally deformed, so that the container can not be stably placed at a normal upstanding posture and it becomes difficult to pile another container thereon.
In order to solve the above problems, it is considered to use a ring-shaped rubber protector as a protector. Japanese Design Registration No. 635034 (a keg to be used for transportation) discloses this example, i.e., rubber protectors are fitted to an upper portion and a lower portion of a container body, as shown in FIG. 23.
In FIG. 23, when a rubber protector is used, it is necessary to provide a certain thickness to a ring-shaped portion for maintaining strength. Accordingly, protectors 61 must be fixed on a smooth curved surface of an upper end wall 63 of a container body 62 and that of a lower end wall 64 of the container body 62, respectively. Since a keg shown in FIG. 23 is a relatively long and slender container and the areas of the upper end wall 63 and the lower end wall 64 are small, there may be no special problem in a point of strength. However, when this keg is used as a beer keg and a container body is formed by deep-drawing a stainless steel plate, a girth or shell portion of the container is hardened during the working, so that the strength of the girth portion is remarkably increased. However, strains are not formed on the end wall faces of the upper and lower end walls which become fitting portions of the protectors and thus, there is no change in strength when compared with that of a stainless steel plate which is unworked.
When a rubber protector 70 is fitted to an end wall face 71 of the upper or lower end wall in a state such that the strength is low as shown in FIG. 24, the end all face 71 of the upper or lower end wall is easily depressed like a portion 71' by load applied thereto in the perpendicular direction at the piling step of the kegs or by impingement to the rubber protectors when the keg is turned over. According to a degree of depression, the form of the rubber protector 70 gets out of shape to result in useless as the container. Moreover, the container can not be placed stably.
As another example, in a case here a ring-shaped protector is used, an inner peripheral edge 70a of a protector 70 as shown in FIG. 24 is extended in the central direction to be fixed smoothly to a smooth curved face of an end wall face 71. As a result, there occurs such a problem that as the end of an inner edge of the protector 70 becomes thin in thickness, the end of an inner edge is easily deteriorated, and it is liable to be come off due to an insufficient adhesion.